Caliper attachment.



W. M. MAHONEY. GALIPER ATTACHMENT.

APPLICATION FILED JULY 31, 1911.

Patented Jan. 30, 1912.

WITNESSES.-

#41 A TTORNEYJI UNITED STATES PATENT OFFICE.

WILLIAM M. MAI-IONEY, OF TOLEDO, OHIO.

CALIPER ATTACHMENT.

Specification of Letters Patent. Application filed July 31,

Patented Jan. 30, 1912.

1911. Serial No. 641,475.

To all whom it may concern Be it known that I, WILLIAM M. MA- HONEY, acitizen of the United. States, and a resident of Toledo, in the countyof Lucas and State of Ohio, have invented. a certain new and usefulCaliper Attachment; and I do hereby declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which itappertains to make and use thesame, reference being had to the accompany- 1 ing drawings, and to thefigures of reference marked thereon, which form a part of thisspecification.

In the use of both inside and outside calipers considerable difiicultyis experienced in securing accurate adjustment of the same for finework, as the adjustment obtained in the ordinary way usually varies athousandth or more of an inch.

The object of my invention is to provide operable to effect a lateralspringing or adjustment of the free end portion of the caliper leg towhich it is attached relative to the other leg to effect a minuteVarying of the distance between the caliper points,

thus enabling a very fine adjustment of the same to be secured.

The invention is fully described in the following specification, andwhile, in its broader aspect, it is capable of embodiment in numerousforms a preferred embodiment thereof is illustrated in the accompanyingdrawings, in which, a

Figure l is a side elevation of my invention attached to a caliper. Fig.2 is an edge elevation thereof with the free end of one caliper legsprung slightly laterally from the plane of the other. Fig. 3 is anenlarged side elevation of the attachment comprising the invention. Fig.4 is an end view thereof. Fig. 5 is a diagram illustrating an eflectedadjustment of the legs of a caliper, and Fig. 6 is a modified form ofthe invention.

Referring to the drawings, 1 and 2 designate the two legs of a caliperwhich are frictionally hinged together at their inner ends as indicatedat 3. The attachment comprising my invention is shown in the presentinstance as consisting of a bar 4 of iron or other suitable materialwhich is of a stiffer or less resilient nature than the leg of thecaliper to which it is to be attached, and has a finger or lug 5projecting laterally therefrom intermediate its ends and preferablyadjacent the rear end thereof and bending i back-upon the bar in spacedrelation thereto. A screw 6 is threaded through the lug 5 in position tobear against the caliper leg in opposition to the bar 4 to cooperatetherewith to grip such leg as indicated in Figs. 1 and 2. WhileI haveshown a particular form of clamp, I wish it understood that any suitablemeans for clamping the bar 4 1 to a caliper leg may be employed.

An adjusting screw 7 is threaded through the outer end portion of thebar 4, or that 'which is disposed adjacent the free end of theassociated caliper leg, to bear laterally ing of the attachment thereto.It is thus apparent that an inward turning of the screw 7 in contactwith the associated caliper leg will effect a lateral springing of suchleg by to vary the distance between the two 1 points of the caliper, thefulcrum or springing point of the leg to which the bar 4 is attachedbeing at or adjacent the point of clampingof the bar 4 thereto, asindicated in Fig. 2. The adjustment thus effected is gram in Fig. 5 ofthe drawings. In this :diagram the line ab indicates the line in whichthe caliper points normally stand with the points at the spots indicatedthereon. If the point of one leg of the caliper is now to be sprunglaterally relative to the line ab any desired distance, as, forinstance, to the point 0, it will be apparent that the line ac or anyline which is laterally oflset from the point I) will be greater inlength thanthe line 0-6, the difference in length of the two linesincreasing in proportion to the length of the line b-0.

In Fig. 6, which illustrates a slightly different form of my invention,8 designates the bar member thereof, which is' provided at or adjacentto its ends with oppositely projecting lugs 9 for engaging the oppositeand has a screw 10 threaded through the central portion thereof forbearing against the associated leg intermediate the lugs 9 andcooperating with the bar and said lugs to effect a bowing of the leg anda consetive to the other leg.

In the use of my invention, it is found in practice that aten-thousandth of an inch adjustment can be secured, thus renderingrelative to the other leg of the caliper wherebetter understood byreference to the diaside of a caliper leg to the body of the bar.

against such leg without the point of damp quent springing of the freeend thereof relamy attachment of exceptional value for use in thesecuring of caliper adjustments for fine work.

I wish it understood the lateral adjustment referred to herein hasreference to an adjustment of the free ends of the caliper legs atsubstantially right angles to the opening and closing movements thereofas distinguished from a relative adjustment of the caliper legs upontheir pivot; and also that my invention is not limited to any specificconstruction or to use in connection with any particular form of caliperexcept in so far as such limitations are specified in the claims.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is,'-

1. The combination with an instrument of the class described, of meanscarried thereby and operable to laterally adjust the free end portion ofone caliperleg relative to the other. I

2. The combination with a caliper, of means capable of being attached toa leg thereof and operable to spring the free end portion of one caliperleg laterally relative to the other leg.

i and capable of cooperating therewith to effecta lateral springing ofone caliper leg relative to the other.

4. The combination with a caliper, of a bar-like member clamped to oneof the caliper legs longitudinally thereof, and means cooperating withsaid member at a distance from the point of attaching of the member tothe leg to effect a lateral springing of the free end of such legrelative to theother.

5. The combination with a caliper, of a bar-like member clamped to oneof the caliper legs longitudinally thereof, and a screw threadingthrough said member at a distance from the point of clamping thereof tothe caliper leg and capable of bearing against the leg toeffect alateral springing of the free end thereof relative to the other leg ofthe caliper.

6. The combination with a caliper, of a bar-like member bearing againstone side of a caliper leg and having a lugextending laterally therefromaround and spaced apart from the opposite, side of" the caliper leg, aclamping screw threaded through said lug to clamp the interposed caliperleg in op position to said member, and a screw threaded through saidmember at a distance from the point of clamping of'the same to the legand capable of cooperating with said memher to effect a lateraladjustment of the free end of the associated leg.

In testimony whereof, I have hereunto signed my nameto thisspecification in the presence of two subscribing witnesses.

' WILLIAM M. MAI-IONEY. Witnesses:

C. W. OWEN, E. E. HoMAs.

Copies of this patent may be obtained for five cents each, by addressingthe. Commissioner of Eaten-ts,

Washington, D. G. i

